<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #d1 {
            width: 100px;
            height: 50px;
            background-color: red;
            position: absolute;
            /*控制限制层级,默认值是0,值越大显示越靠前*/
            z-index: 1;
        }

        #d2 {
            width: 50px;
            height: 100px;
            background-color: blue;
            position: absolute;
            z-index: 2;
        }
        #d0{
            width: 200px;
            height: 200px;
            border: 1px solid red;
            /*溢出设置*/
            overflow: hidden;/*隐藏*/
            overflow: visible;/*显示(默认)*/
            overflow: scroll;/*滚动显示*/
        }
    </style>
</head>
<body>
<div id="d0">
    <img src="../b.jpg">
</div>
<div id="d1"></div>
<div id="d2"></div>
</body>
</html>